cros_bundle_firmware: Support writing images to Dediprog EM100

The Dediprog EM100 is a useful device for emulating SPI flash. We can
write to it over USB using the em100 tool.

BUG=chromium-os:31624
TEST=manual
$ cros_bundle_firmware -b link -w em100 -u u-boot.bin
See that the board boots the new image

Change-Id: Icc56f2ca7f1744a495d481ee6e36c1734205b25f
Reviewed-on: https://gerrit.chromium.org/gerrit/24768
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Ready: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
1 file changed